Fix auto-imports inserting import in CJS files under node16/node20/nodenext

[Copilot]

With module: "node20" (or node16/node18/nodenext) and a tsconfig.json, auto-imports incorrectly emit import statements in CJS files instead of require() calls.

Two problems in computeShouldUseRequire():

• moduleDetection: "force" (the default for Node module kinds) sets ExternalModuleIndicator on all files unconditionally, so the CJS/ESM content heuristic can't distinguish CJS files from ESM files
• GetEmitModuleKind() < ModuleKindES2015 returns false for Node module kinds (ModuleKindNode20 = 102) even though the file may be CJS

Both cause the function to return false (use import) before reaching GetImpliedNodeFormatForEmit(), which would have given the correct answer based on file extension and package.json "type".

Fix

Add an early exit for Node module kinds that delegates directly to GetImpliedNodeFormatForEmit():

moduleKind := v.program.Options().GetEmitModuleKind()
if core.ModuleKindNode16 <= moduleKind && moduleKind <= core.ModuleKindNodeNext {
    return v.program.GetImpliedNodeFormatForEmit(v.importingFile) != core.ModuleKindESNext
}

For Node module kinds, the runtime format is authoritatively determined by file extension and package.json "type" — file content indicators are unreliable under force detection.

Tests

Two new fourslash tests covering the exact scenario from the issue:

• CJS file with existing module.exports syntax + module: "node20" + package.json "type": "commonjs"
• Empty CJS file (same config) — the edge case where ExternalModuleIndicator alone causes the wrong result